By making the concept of "objective truth" problematic, the pragmatic distrust of foundations expands the range in which metaphor and other forms of emotive argument may legitimately upset belief. In Holmes's pragmatic metaphor of the marketplace of ideas, competing theorists, ideologues, and reformers hawk their intellectual wares. Knowing how important persuasion is in the market for goods and services, we should not be surprised to find it playing a big role in the market in ideas as well. We should expect change in law to be related not only to politics and economics and not only to the correction of error, but also to new slogans, metaphors, imagery, and other means of bringing about changes in perspective.

XREF: Connects to Holmes's marketplace of ideas and broader pragmatic traditions in American legal thought.

Richard A. Posner, Richard A. Posner - What Ha…, loc. 137